Ballpark

Calibrate unfamiliar numbers while you read. Click any underlined figure for context and comparisons.

You're reading that a cybersecurity startup raised a $28M Series B, a biotech enrolled 180 patients in its Phase II trial, or a hardware brand runs 34% gross margins. Is that big? Small? Normal for that field? If you don't live in the industry, you have no reference frame — and your existing intuition often misleads you. A 34% margin is alarming for SaaS but healthy for physical goods. A $28M Series B is small for AI but generous for security tooling. Ballpark gives you a quick directional sense, in place, without leaving the page — it underlines numbers as you read, and a click brings up a small card with context and comparisons. And it stays out of your way: Ballpark won't run on your email, bank, shopping, or internal work tools, so it only shows up where calibrating a number actually helps. COST Roughly 80–100 numbers per dollar — about 1¢ per click. The exact cost varies with the page and whether a web search runs; you can track it on your Anthropic Platform dashboard. GETTING STARTED A setup guide loads automatically when you add the Ballpark extension. With an API key ready, setup takes <1 min. To reopen the setup guide anytime, click the Ballpark icon via the Extensions (puzzle-piece) menu. HOW IT WORKS - Free, open-source software (MIT license) — you pay only Anthropic for the calls you make - Requires your own Anthropic API key — calls go directly from your browser to Anthropic. There is no Ballpark server, and your data never passes through us - Finding and underlining numbers happens locally in your browser and is never sent anywhere Privacy policy: https://www.treebirdlabs.com/ballpark/privacy Source code: https://github.com/treebirdlabs/ballpark